HOW TO MAKE TOMATO POWDER

Rinse the tomatoes and peppers well and remove the stems.
Slice your tomato into ¼-inch slices and line them on a flat tray or surface.
Spread the tomatoes out so that they don’t lie on top of each other.
Keep the tray in a very sunny spot until they're perfectly dried,
If you notice some houseflies, you can put some mesh material over the tomatoes, to keep the flies away from getting to it.
After drying, the tomatoes for two days and they are still flexible,

Don't be in hurry to take them away from the sun, there is likely a tiny bit of moisture. You can flip the tomatoes partway through the process for them to dry inside out.
Once the tomatoes are dried and brittle, it means the moisture has been thoroughly removed.
Bring the dried tomatoes into a blender or food processor, blend into a smooth powder. Store the tomato powder in a Mason jar or airtight container and use when needed.